tag:blogger.com,1999:blog-4786784182488135171.post817960139688017329..comments2023-07-21T17:26:24.127+04:00Comments on Ron George: Deceleration And Force Of A Helmeted Head ImpactRonhttp://www.blogger.com/profile/16268869622833968439noreply@blogger.comBlogger8125tag:blogger.com,1999:blog-4786784182488135171.post-32177709254365237842009-07-06T21:04:12.427+04:002009-07-06T21:04:12.427+04:001. My understanding is that even in collisions tha...1. My understanding is that even in collisions that did result in injury to the brain there was little compression of the foam. If that is correct then SURELY the foam is too stiff? I would personally rather have a helmet that "runs out" of cushion (just) before I get brain damage, than one which will still have travel left long after the acceleration on my head becomes critical.<br><br>2. I understand that angular acceleration is often thought to be far more serious than direct impact, but arent we still looking at (broadly) a situation in which the initial angular acceleration is still the critical factor?<br><br>4. My point is that the deformation of the skull will effect how the helmet is loaded rather than the brain. In turn, a lower pressure on the helmet would necessitate a less stiff foam.gsport georgehttps://www.blogger.com/profile/10070707288565019602noreply@blogger.comtag:blogger.com,1999:blog-4786784182488135171.post-35038044188616736902009-07-02T02:47:36.647+04:002009-07-02T02:47:36.647+04:00Ron, the design brief said the objective was to cr...Ron, the design brief said the objective was to create something for minor bumps and falls. The issue of buckling seems real, so my question is ...after a minor fall, is it elastic enough to come back into its original shape? Who knows. Its still not a bad idea, and it looks like it will really excel in the cooling of the head.Bike_Boyhttps://www.blogger.com/profile/16268869622833968439noreply@blogger.comtag:blogger.com,1999:blog-4786784182488135171.post-85014898794892215712009-07-01T14:52:55.705+04:002009-07-01T14:52:55.705+04:00The honeycomb/folding design looks really neat, yo...The honeycomb/folding design looks really neat, you can see comfort and ventilation being very good. However I think there is an inherant problem with using a member that will buckle, as I would think these ribs will. The stiffness will start at a maximum, tail off slightly as it begins to buckle, then drop almost to zero once buckling really starts. I suppose with this shape, as the first ribs to hit buckle, others will come into play as they make contact, so that may counteract it somewhat, however you are giving up any protection in the initial zone..<br><br>Chances of selling a helmet that looks like that and ties on with a ribbon like a bonnet to serious cyclists in any discipline? Pretty much zero I would think...gsport georgehttps://www.blogger.com/profile/10070707288565019602noreply@blogger.comtag:blogger.com,1999:blog-4786784182488135171.post-45550278539163896682009-06-30T08:03:51.759+04:002009-06-30T08:03:51.759+04:00Interesting discussion. May I also add the mythbus...Interesting discussion. May I also add the mythbuster's use pig cadavers. The ethical implications of using animal body parts are many. I still think if you want to save a human's life, its best to test on a human cadaver.Stan Slevinskinoreply@blogger.comtag:blogger.com,1999:blog-4786784182488135171.post-76918186060858788852009-06-30T03:42:53.061+04:002009-06-30T03:42:53.061+04:00There's a reason those mythbusters use ballist...There's a reason those mythbusters use ballistics gel to simulate human heads when blowing them up.Ronhttps://www.blogger.com/profile/18394865788996482667noreply@blogger.comtag:blogger.com,1999:blog-4786784182488135171.post-87564949821488756402009-06-29T06:25:34.286+04:002009-06-29T06:25:34.286+04:00I really really like your blog,Ron. Its very diffe...I really really like your blog,Ron. Its very different&interesting.Keep up the good work.<br>GabGabbienoreply@blogger.comtag:blogger.com,1999:blog-4786784182488135171.post-68299775235870683672009-06-28T02:45:32.488+04:002009-06-28T02:45:32.488+04:00Vary unique blog.Bicycles math!Vary unique blog.Bicycles math!Major Taylorhttp://marshalltaylor.blogspot.comnoreply@blogger.comtag:blogger.com,1999:blog-4786784182488135171.post-44675965791411359162009-06-27T04:28:03.448+04:002009-06-27T04:28:03.448+04:00Ron, your comment about using ballistics gel to si...Ron, your comment about using ballistics gel to simulate the head may not be practical as high vibrations in it might make the mean accelerations difficult to compute in a test simulation. Thanks.John K.noreply@blogger.com